I've just published draft #2 of SRFI 140. It was submitted
by Per Bothner, the author. Among other things, Per has
renamed the SRFI, originally called Strings for WG2, to
Immutable Strings.
<http://srfi.schemers.org/srfi-140/>
Here's the diff:
<https://github.com/scheme-requests-for-implementation/srfi-140>
Regards,
SRFI Editor